Backup: Do you have a verified backup of $HOME yet? (Rhetorical question, of course you do).
Windows will stomp all over your Linux install, so Windows must go on first.
Then, reinstall 10.04 LTS (or think seriously about upgrading to 12.04 with the Xfce GUI) and
restore your $HOME data.
Wish I had a simple, straight forward way to do that without reinstall, but Windows won't permit it.